(CNN) -- You're delayed at the airport. It's going to be hours before the airline can get you on another flight. You log onto your computer and answer your e-mails. You surf the Web for a while. You're still waiting. This is taking way too long.

JetBlueCheeps on Twitter alerts followers of last-minute deals on JetBlue.

Might as well tweet about it.

And if you do, the chances are ever increasing that someone at the airline will see what you have written. They may even respond to it.

Airlines are ramping up their use of social networking sites. Several have one employee in the communications department whose primary job is to monitor what is being said about them and to create a presence in the world of Twitter and Facebook. Other staff members also watch the sites in search of opportunities to improve relationships with customers.

"Promotions clearly work well, but there is also an opportunity for airlines to improve customer service and brand perception," Adam Ostrow, editor-in-chief of social media guide Mashable.com and a commentator on social networking sites, wrote in an e-mail interview. "If you're stuckat an airport, and it's the airline's fault, you're going to tweet about it. If the airline responds to those tweets in a positive fashion, it at least shows they care, even if they can't immediately remedy the issue."

JetBlue has embraced Twitter as both a medium to update the public on its latest news and a sounding board for how the airline is doing.

The airline has more than 1 million followers on Twitter and it also follows about 120,000 of those tweeters.

"The tricky thing with following people is that you don't want to creep anyone out," said Alex Headrick, senior analyst of corporate communications at JetBlue. "You don't want to look like you are stalking them just because they are talking about us."

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The trick is to watch them and see if the tweeter is trying to actively engage the airline in conversation, he said. Often when that happens, someone from the company will send a private message to thatperson.

The main goal for JetBlue is to "humanize the brand," Headrick said.

Like other airlines, JetBlue approached social networking sites by slowly scaling up its presence.

American Airlines also took its time. Billy Sanez, director of customer communications, said the airline has been watching the growth of social media for several years.

The interactive team brought up the idea of using Facebook about a year ago, Sanez said, and the airline added its fan page about four months ago. It has been increasing its use of the site by adding modules, including a yet-to-be-named feature that helps users find fares.

"We still have a lot to learn from customers and from how customers interact in these mediums," he said. "But it has worked because we have been able to do targeted promotions to consumers, and because we have been able to get feedback from consumers, and in a very easy way."

Not to mention an inexpensive way. Mashable's Ostrow said social media is still a small part of most marketing budgets (not only for airlines but for many companies) but it is attractive because the costs are minimal.

"It also can be essentially cost-free to get started, since all one needs to do is open a Facebook, Twitter or YouTube account and get creative," Ostrow said. "In a down economy, the low cost of entry certainly makes social media even more attractive than it might have already been otherwise."

As for the unfavorable comments people post, American Airlines' Sanez says it can be a chance to turn a negative experience into something positive. He thinks it can be good for customers to use the forum to get something off their chest.

The airline looks for opportunities to interact with users. If people want to express something, let them express it, he said. If they are frustrated, they should be able to complain.

"If they want a resolution, we want to engage them and come up with options and get them to the right people with the right information," he said.

Twitter followers and Facebook fans can also get the scoop on fare sales. JetBlue has a Twitter feed called JetBlueCheeps, where travelers can get some last-minute deals. For instance, on Monday, September 7, the airline posted on its Twitter feed that there were 25 seats available on a flight from New York's LaGuardia to Orlando, Florida, for $39. Tickets for the Saturday flight had to be purchased by 6 p.m. Monday evening.

Headrick said that JetBlue times Twitter updates to coincide with releases to the media.

While airlines appear to be happy so far with the results they are getting from their social media ventures, some are still not ready to expand dramatically just yet. Headrick said JetBlue was studying how to use Facebook.

Meanwhile, Southwest Airlines has established its social media presence with more than 600,000 followers on Twitter and more than 76,000 fans on Facebook.

Other major carriers also have thousands of followers on Twitter. Delta Air Lines, for instance, has about 11,000 followers, while United Airlines has more than 33,000 watchers.

Continental is also looking at Facebook and other sites where a presence makes sense, according to airline spokeswoman Mary Clark. Continental is focusing on Twitter, where it has about 3,000 followers, and FlyerTalk.com, a Web site devoted to frequent flyers, she said.